Closure cap assembly with magnetically operable liquid level indicating means



Er; 5:1 :51 ti-WUH ROOM Feb. 27, 1968 D v. HEALY 3,370,467

CLOSURE CAP ASSEMBIJY WITH MAGNETICALLY OPERABLE LIQUID mavm mmcmme EANS Filed March 12, 1965 y 2 Sheets-Sheet 1 INVENTOR. flan/440 %/L/EAV W m w /4r70e/v/5$ 5 Feb. 27, 1968 D. v. HEALY 3,370,467

CLOSURE CAP ASSEMBLY WITH MAGNETICALLY OPERABLE LIQUID LEVEL INDICATING MEANS 2 Sheets-Sheet 2 Filed March 12, 1965 United States Patent 3,370,467 CLOSURE CAP ASSEMBLY WITH MAGNETICALLY OPERABLE LIQUID LEVEL INDICATING MEANS Donald V. Healy, 24455 Arcadia St... Newhall, Calif. 91321 Filed Mar. 12, 1965, Ser. No. 439,401 11 Claimsu (Clc 73-306) ABSTRACT OF THE DISCLOSURE was This invention relates to a removable closure cap assembly embodying visual means for indicating liquid level in closed containers and, more particularly, to a cap assembly of this type for pressurized containers, such as automobile radiators.

It has become common practice in recent years to pressurize automobile cooling systems. This has the advantage of raising the boiling point of the coolant, which, in turn, enables it to absorb more heat per unit volume, as well as reduces the incidence of coolant-loss by boiling it out. In addition, it minimizes the loss of coolant by evaporation under normal operating conditions. The result is a safer and more efiicient system.

These advantages, particularly as regards the conserva" tion of coolant, are reduced, if not totally lost, if the system is open to the atmosphere when the engine is at operating temperature or above. Should this occur, coolant escapes through the opening. In practice, this frequently occurs at filling stations where an attendant removes the radiator cap to check the level of the coolant. This also poses a serious safety hazard, since, if the attendant is not extremely careful, he can be burned by the escaping gas and liquid.

Before lost coolant can safely be replaced, the system temperature must be allowed to drop at least a few de grees which obviously takes time. .As a consequence, the cap is frequently replaced by a hurried attendant and the automobile is driven away with the coolant supply depleted. This, of course, decreases the efficiency of the system. Moreover, even if the coolant is replaced, this is still an unsatisfactory situation. Besides the potential safety hazard, the coolants commonly used comprise mixtures of water and other compounds or liquids other than water, the latter of which are generally relatively costly.

Another problem commonly encountered in pressurized cooling systems stems from the fact that a vacuum is drawn in the system when the engine is shut off and allowed to cool. During normal engine operation, the system pressure builds up to the maximum or control level and remains there, such pressure normally being controlled by pressure-relief means on the cap. When the engine is subsequently shut oif and the system cools down, the effect is to draw a vacuum in the head space in the system, which is then sealed from the exterior. This is undesirable from the standpoint that it often collapses flexible hoses and the like, thereby weakening, if not permanently damaging them.

In view of the foregoing, it is a primary object of the invention to provide an improved removable closure cap assembly which obviates the problems of the prior a t.

A more specific object is to provide an improved closure cap assembly for a container which enables the liquid level in a container to be quickly and easily determined by visual inspection from the exterior without removal of the cap assembly.

A further object is to provide a closure cap assembly of the type described especially adapted for safe and effective use On a pressurized container, such as an auto= mobile radiator.

A related object is to provide a cap assembly of this type further characterized in that it automatically relieves excess positive pressure in the container.

Another object is to provide a cap assembly of the type described further characterized in that it embodies means for relieving automatically negative pressure with in the container.

Still another object is to provide an improved cap as sembly of the type described with manually operable means readily accessible and easily used for venting the container to the exterior prior to removal of the cap assembly.

It is a further object to provide such a cap assembly which is highly economical from the standpoint of con serving liquid stored in the container.

It is another object to provide an improved closure cap assembly for a container embodying means for visually indicating the liquid level therein which assembly is strong and durable and trouble-free in operation.

A still further object is to provide an improved closure cap assembly capable of accomplishing all of the foregoing objects, yet which is relatively simple in construc tion and readily adapted to be manufactured at low cost.

These and other objects, features and advantages of the invention will be better understood from the following detailed description taken in conjunction with the ac companying drawings, in which:

FIGURE 1 is a vertical sectional view of the cap assembly of the invention installed on a conventional automobile radiator with certain parts being shown in. elevation for added clarity;

FIGURE 1a is a fragmentary side elevational view taken in the direction of the arrowed line 1a in FIG URE l and having the exterior part broken away and removed to show the underlying part more clearly;

FIGURE 2 is a partial top plan view of the cap assem bly of FIGURE 1;

FIGURE 2a is a fragmentary sectional view taken. along the line 2a-2a of FIGURE 2;

FIGURE 3 is a perspective view of a rotatable, but axially immovable, support assembly shown centrally in vertical section in FIGURE '1;

FIGURE 4 is a view similar to FIGURE 1. of a modi fied version of the cap assembly of the invention; and

FIGURE 5 is a perspecti e view of a guide assembly shown centrally in vertical section in FIGURE 4.

Referring to the drawing and, in. particular, to FIG= URE 1. reference numeral 10 designates the presently preferred embodiment of the cap assembly of the inven-= tion. In general, the assembly includes a cap 12 mounting an elongated, hollow shroud 14 centrally thereof. The shroud 14 is supported on. said cap for limited vertical movement relative thereto, and in turn, houses a mov= able float assembly 16 and mounts externally at its upper end rotatable dial means 18. A helical cam assembly 20 is disposed within the shroud in operative association with the float assembly 16 and arranged to produce rota tional movement in response to vertical movement of the latter. Means are provided on the dial means 18 and on the cam assembly 20 for magnetically coupling these two elements, so that the vertical position of the float assem bly is reflected by the angular position of the dial means.

age-nuts? As noted in the introductory portion aibove the cap assembly of the invention finds advantageous use on an automobile radiator, and, for this reason, it is described as especially adapted therefor: in FIGURE 1, the as sembly as shown as installed. on a conventional radiator 22 having a top opening 24 and a filler neck. 26 with a flanged lip 28 at its upper end, The filler neck .26 is con figurated to provide an upwardly facing lip 30 adjacent the junction with the opening 24.. An overflow pipe 32 vents the filler neck 26 to the exterior. The cap assembly 10 may be used to advantage on a. variety of other applications and, therefore, the detailed description of. this particular adaptation is not. intended to be limita= tive.

The cap 12 is arranged for locking engagement on the flanged lip 28 of the filler neck. 26, It includes, in series, a lid 34 with a central opening 35, a depending skirt 36 and inturned locking flanges 38 at diametrically opposed positions on the skirt Portions (not shown) of the flanged lip 28 are slotted to receive the flanges 38 as the cap is positioned for installation. The flanges then. engage under the lip 28 upon rotation of the cap into locking engage ment, as illustrated in. FIGURE 1. Preferably, the cap 12 is formed of a. strong, durable and corrosion=resistant metal.

The shroud 14 comprises an elongated and. generally sleeve-like member which is open at its lower end and closed at its upper end It is necked down adjacent its upper end in order to provide an external, upwardly fac ing shoulder 42. Preferably, the upper end 44 of the shroud is conically shaped and faces upwardly in order to aflord good bearing support, as will be developed more fully below. The shroud 14 is oriented generally vertically and arranged centrally of the cap 12 with its upper end 44 projecting upwardly through the central opening 35 in the cap 12 just slightly above the lid 34.

In order not to interfere with the magnetic coupling between the dial means 18 and cam assembly 20, at least the upper end portion of the shroud 14 is formed of a material which is both non=magnetic and. magnetically penetrable. Like the cap, it is also preferred that it be strong, durable andv corrosion-resistant? Certain metals have 'been found to be suitable.

The float assembly 16 is slidably disposed in protective relation within the lower end portion. of the shroud l4 and arranged for vertical movement therein in accordance with changes in liquid level in the radiator 22, as sembly 16 includes a float 48 and an axially disposed and upwardly projecting rod 50, formed integrally with the upper end of the float. The float 48, in turn, comprises any suitable member which is buoyant in. liquids com= monly used as coolants. In. the illustrative case, it is formed as a hollow member with integral top and. side walls and having a flat disc 52 sealed in a. recess in its lower end. The float assembly, preferably, is formed of a lightweight material which is strong and durable. Satisfactory results are achieved by forming it of various plastics including polyester resin.-

In order that the dial means 18 will function properly, it is desired to restrain rotation of the float assembly 16. To accomplish this and still allow for its vertical mvement, cooperating means are provided on the shroud 14 and float assembly 16. Such means here comprise an internally grooved guide sleeve 54., preferably formed of plastic, and a cross pin 56 supported on the rod 50. The guide sleeve 54 is shaped externally to correspond gen erally to the internal configuration of the shroud and is press fit therein. In addition, the sleeve is locked in place and indexed 'both. axially and rotationally with respect to the shroud by a pair of diametrically opposed lugs 58 (FIGURES 1 and 1a) receivable inv apertures 60 in the shroud. Axially extending grooves '62 are provided at diametrically opposed locations in the sleeve for receiving the opposite ends of the pin 56. Such grooves extend a ill ill 4 sufficient axial distance to accommodate the full range of vertical travel of the float. assembly.

The cross pin 56 is rigidly secured in. place on. the rod by virtue of being received. in an interference fit in a cross bore 64 in the rod The pin is, of course, sized in relation to the grooves 62 to insure that it is freely received therein and does not appreciably restrain. vertical movement of the float assembly 16,

Translation of the vertical float. movement to corresponding rotational movement is achieved by the cam assembly 20, illustrated in FIGURES l and 3, This assern= bly comprises a. sleeve-dike lower portion. 66 with an axial. rod 68 projecting upwardly therefrom, Identical helical slots 70 are provided at. diametrically opposed positions in the side walls of the portion. 66, commencing at its lower end and extending upwardly over a distance corresponding at least to the :full range of vertical travel. of the float assembly. The cam assembly 20 is disposed Within the shroud. l4 and positioned with its lower por tion 66 around the upwardly projecting axial rod 50 of the float assemblyq These helical slots '70 receive the corresponding end. portion of ime cross pin 56 which extends through the slots and. into the grooves 62 in the guide sleeve 54,

The cam assembly 20 is arranged within the shroud for rotational. movement, but restrained against axial movement. Such restraint is accomplished. by the magnetic coupling between the dial means 18 and the cam assent bly 20.. Moreover, any appreciable axial movement is prevented by a cross pin 71, at the upper end of the rod 68, which. is of a length greater than the diameter axial passage through the guide sleeve 54, Accordingly, vertical movement of the float assembly 16 in response to changes in liquid level within the radiator 22 produces rotational movement of the cam assembly;

Assembly of the various elements within the shroud 14 may be quickly and easily accomplished. The cam assembly 20 is first inserted in guide sleeve 54 and pin 71. is pressed in. place sub-assembly is then placed in shroud. 14 and the lingers .72 on the lower end of the shroud 14 are bent inwardly to limit downward movement of the float. assembly 16 and retain it in assembly with the shroud As set forth above, the dial means 18 serves to indicate the axial position of the float assembly 16 within the shroud 14 and, hence, the liquid level in the radiator. Sup port for the dial. means 18 is provided by an annular col lar 74 formed of a nonmagnetic material and secured to the upper end portion of the shroud 14 by any suitable means, as by spot welding, The collar 74 is configurated to provide an inner, downwardly facing shoulder "76 at a location spaced just downwardly from the upper end of the shroud and. an. outer, upwardly facing shoulder 78 at a location spaced just: slightly above the upper end. of the shroud The cylindrical. section of the collar intermediate the shoulders 76 and 78 has an outside diameter just slightly less than the diameter of the opening in the cap to allow for relative sliding movement. Further, the terminal flange 80 at the upper end of the collar 74 slopes slightly inwardly and is arranged to receive in tight titting engagement a transparent viewing dome 82a The dome 82, turn, has a. recessed central portion 84 which coop-= erates with the collar 74 to define an internal. chamber for mountingthe various movable parts of the dial means An indication of the liquid level. within the radiator 22 is afforded by the horizontally arranged and rotatable pointer 86. Rotatable mounting is accomplished with a. rivet 87 with. a dished or concave head 88 that rests in bearing contact on the upper end 44 of the shroud. The opposite or shank end of the rivet, in turn, has bearing support within an upwardly directed bore 89 in the view ing dome 82. The pointer 86 is pressed onto the shank and held against movement relative thereto by upsetting the end of the ri env shank over a washer 91 so as to draw the parts tightly together. Suitable indicia, such that indicated in FIGURE 2, may be provided on dial plate 90 interposed between the shoulder and. r marginal edge of the viewing dome, Appropriate sections of the plate 90 may be painted different. colors in the manner shown in. FIGURE 2 to simplify reading of the dial means,

Preferably, in order to insure that the movement of the pointer 86 is always correlated with that: of the float assembly 16, means are provided on the plate for limiting its angular movement to less than 180, Such means may be seen to comprise a pair of upstanding projections 92 formed as cutouts in the plate 90* (FIGURE 2a), These projections engage the pointer at the opposite limits of its travel in the manner illustrated in FIGURES 2 and 2a, The plate is, of course, angularly indexed so that when the float assembly 16 is in its lowermost position, the pointer 86 is on the LO side of the plate 90, as indicated in phantom lines in FIGURE 2, On the other hand, when the float assembly moves upwardly to the upper position shown in FIGURE 1, the pointer moves to OK side of the plate.

To magnetically couple the cam assembly to the dial means, various combinations of magnetic means or magnetic and magnetically attractable-means may be em. ployed. In the illustration the cross pin 71 on. the upper end of the cam assembly 20 comprises a permanent mag net and a U-shaped, magnetically attractable member 94 is fixed to the rivet 87, Thus, the member 94 serves as a follower and moves in accordance with movement of the pin 71 to maintain their angular alignmenta In this con-- nection, it will be recalled that the shroud formed of a non-magnetic and magnetically penetrable material and, thus, does not interfere with. this magnetic coupling. Mounting of the member 94 is achieved by interposing it between the head 88 of the rivet 87 and the pointer 86 which, in turn, is finmly secured in place by the locking ring 91.

A particular advantage of the cap assembly of the in= vention is that very little force is required. on the float sembly to overcome friction to move it and produce a. corresponding indication on the dial means 18. Attention is drawn to the fact that the magnetic attraction between the pin 71 and member 94 serves to hold the cam assembly upwardly in the manner shown in FIGURE 1, with the pin 71 off the shoulder afforded by the end of the guide sleeve 54. Further, in order to minimize the force required, the upper end 96 of the :rod 68 is conical ly shaped and engages in essentially point contact with the upper end 44 of the shroud 14, In addition, radial enlarge= ments 98 on the rod 68 of the cam assembly 20 and a similar enlargement 100 on the rod 50 of the float. as sembly 16, serve effectively as bearings,

As is conventional with modern automobile radiators, primary sealing is provided at the lip adjacent the juncture of the filler neck 26 with the top opening 24 in the radiator 22. To accomplish sealing at this location, the cap assembly is provided with an annular poppet plate 102 disposed around the reduced upper portion of the shroud 14 and arranged to engage both the shoulder 42 on the shroud 14 and the lip 30. To enhance the seal, a resilient, deformable gasket 104 is attached to the under side of the plate 102. The poppet plate 102, carrying the gasket, is urged downwardly into forceful sealing contact with the lip by a main compression spring 106 dis posed around the upper end portion of the shroud and between the plate 102 and central portion of the cap.

Interposed between the upper end of the spring 106 and. the cap 12 is an annular, spring washer 108 formed with a plurality of reversely curving corrugations or ridges. The central corrugation engages the underside of the cap and is held in place by the spring 106, thereby serving to cantilever both the inner and outer marginal edge portions of the washer with respect to the cap. Referring to FIGURE 1, it may be seen that the inner marginal edge portion of the washer 108 engages the inner shoulder on the collar 74 which, in. turn, is fixed to the shroud. Thus, this portion of the washer 108 serves to yieldably resist downward movement of the shroud and. to maintain good sealing contact between the poppet plate 102 and the shoulder 42 on the shroud: When the cap is free of the main spring 106, which has a. substantially greater spring rate than that of the washer, the former acts to urge the shroud downwardly with respect to the cap 12 in opposition to the washer. However, the parts are arranged so that no appreciable force is placed on the washer 108 as the spring 106 extends to its maximum length.

The outer marginal edge portion of the washer 108 is arranged to engage in continuous forceful contact with the lip 28 on the filler neck when the cap assembly is installed in the manner shown in FIGURE 1, Tolerances in the various parts are accommodated and sealing at this location is assured because of the yieldable flexing of this portion of the washer upon such contact.

The material forming the spring washer 108 must retain its spring qualities even after repeated flexing attcndant with frequent installation and removal of the cap assembly and remain impermeable to gases and liquids. It has been found that these requirements are met by forming the seal of a metal such as spring-tempered, phosphor bronze.

In installing the cap assembly 10 for use, its lower end is inserted through the filler neck 26 into the radiator until the poppet plate 102 engages the lip 30. Downward pressure is then applied to compress the main spring 106 slightly and enable the cap 12 to be rotated into tight locking relationship with the flanged lip 28. Coincidentally, the spring washer 108 reacts to maintain the shoulder 42 on the shroud 14 in sealing engagement with the poppet plate 102. In this connection, it Will be ap preciated that only light spring pressure is required, since pressure within the radiator acts to urge the shroud into such sealing relationship. During installation of the cap assembly, the outer marginal edge portion of the spring washer 108 also engages in sealing relationship with the top of the flanged lip 28,

The function of the cap assembly when so installed comprises two separate aspects. The first is that of indicating liquid level within the radiator and the second is that of relief of both predetermined positive and negative pressures within the radiator.

Considering first the function of indicating liquid level, the level is accurately reflected by the pointer 86 of the dial means 18, provided it is within the safe range bounded by the phantom normal and low lines in FIGURE 1, Should the liquid level be higher than that indicated by the normal line, upward travel of the float assembly 16'is limited by the cam assembly 20 and the movement of the pointer 86 is limited by virtue of engaging one of the projections in the manner illustrated in FIGURE 2. On the other hand, if the liquid level goes below the safe range, the float assembly 16 drops to its lowermost position established by the fingers 72 on the shroud 14 and the pointer 86 moves to its opposite extreme position shown in phantom lines in FIGURE 2. In any event, it is readily apparent to a person observing the cap whether the coolant level is within or above the safe range, or be-- low the safe range. In a radiator, the pressure-relief feature of the cap assembly, described below, assures that no damage results from levels above the safe range. Thus, the important thing to be determined is that the level is not below the lower extremity of the safe It will be appreciated that this construction and opera tion of the cap assembly is such that there is virtually no need to remove the cap assembly under normal operat ing conditions. As a result, the safety hazard present when a person removes a conventional cap from a radiator of an engine which is at operating temperature and above is eliminated. Further, coolant is conserved as compared to the situation where a conventional cap is used since none is lost in checking the level, Moreover, since the radiator 22 is sealed under normal conditions, the loss of coolant by evaporation is minimal.

With respect to the pressure-relief aspect of the invention, the cap assembly 10 automatically relieves excess positive pressures within the radiator 22 and relieves negative pressures therein, as well as provides for manual venting of the radiator to the atmosphere.

Should a positive pressure build up within the radiator to a level exceeding the calibrated force of the main spring 106, the poppet plate 102 is yieldably urged upwardly off of the lip 30 to bleed oil gas or liquid between the plate and the lip and eventually out the overflow pipe 32., When the pressure within the radiator subsequently drops to a safe level, the spring 106 reacts to urge the poppet plate back into seated position.

On the other hand, when a negative pressure begins to build up within the radiator, as when an engine is shut off and the cooling system temperature drops, atmospheric pressure acting downwardly on the shroud 14 is opposed essentially only by the force of the relatively light spring washer 108. When this downward pressure exceeds the calibrated force of the washer, the shroud 14 moves downwardly away from the poppet plate 102,

,thus permitting ambient air to enter the radiator through the overflow pipe 32 and filler neck 26.

Manual venting .of the radiator to the atmosphere is desirable in the event it should be necessary to remove the cap assembly. It is accomplished by applying a down ward force to the poppet dome 82 to force the shoulder 42 on the shroud 14 downwardly away from the poppet plate 102, As a consequence, the atmospheric and radiator pressure are quickly balanced, If this is done preparatory to removing the cap, it will be appreciated that the potential safety hazard of burning the attendant is eliminated This follows from the fact that any escaping gas and liquid passes into the filler neck 26 and out of the overflow pipe 32, rather than out through the top open= ing in the filler neck which is then sealed by the cap 12 and spring washer 108 In some applications, it may be possible to further simplify portions of the cap assembly, A so-modifie'd embodiment, designated by the reference numeral 120, is illustrated in FIGURES 4 and 5, The primary difference between the present embodiment and the one previously described resides in the means for producing rotational movement for actuating the dial means in response to vertical movement of the float assembly, Other diflerences in the two embodiments exist in the mounting of the movable elements of the dial means and in the mounting of the shroud on the cap.

To simplify the description, the parts of the present embodiment corresponding to parts of the embodiment previously described have been identified by the same reference numeral carrying a prime subscript,

Referring to FIGURE 4, it may be seen that the float assembly 16 embodies an elongated rod 122 supporting a cross pin 124, comprising a permanent magnet, at its upper end. In this instance, the float assembly itself is caused to rotate as it moves vertically by providing helical slots 126 at diametrically opposed positions on the guide sleeve 54' (FIGURE Accordingly, changes in fluid level in the radiator bring about both vertical and rota= tional movement of the float assembly.

Since the magnetic cross pin. 124 moves vertically in this case, it is necessary to provide the U-shaped follower member 94' of the dial means with elongated side por= tions, To allow for rotational movement of the member, the supprt collar 74 is configurated so as to be spaced away from the periphery of the shroud 14', As the float assembly 16' moves vertically within its full range of travel, i.e., from the upper limit position illustrated in FIGURE 4 to the lower limit position wherein the bottom of the float 48' contacts the fingers 72', there is always 8 a portion of the follower member 94" horizontally adja= cent the pin,

In 'view of the shape of the follower member in this instance, a somewhat diflerent mounting arrangement is provided. A flanged bushing 128 is secured to the upper end of the shroud 14 and rotatably mounts a rivet 87' carrying in fixed relation the member 94, pointer 86' and locking ring 91 By forming the parts so that there is a closed bearing contact between the surfaces of rivet 87' and the bushing 128, the desired rotation can be pro vided for, yet the member can be maintained in concentric relation to the shroud 1da It will also be seen in FIGURE 4 that a separate compression spring 130 is used to maintain sealing relationship between the shoulder 42 on the shroud and the poppet plate 102: This spring engages at its opposite ends the inner shoulder 76" on the collar 74 and the plate 102'. As in the case of the spring washer 108 of the previous embodiment, the spring 130 is considerably weaker than the main spring 106' in order not to interfere with the primary sealing between the poppet plate 102' and the lip 30, Moreover, the spring 130 is calibrated so as to re lieve any appreciable negative pressure within the radiator by enabling the shroud 14' to move down away from the underside .of the plate in response to such pressures.

Sealing is afforded between the cap 12 and the shroud 14' by the O=ring 132 receivable in an annular channel 134 therebetween, The channel. 134 is defined by suit= ably configurating the spring washer 108' so that it co= operates with the adjacent wall of the collar 74' carried by the shroud. Upon relative movement between the cap l2 and shroud 14, the O-ring 130 rides on the opposing surfaces of the collar 74' and washer 108' to afford sealing As noted above, it is only necessary to provide for relatively low pressure sealing at this juncture since the filler neck 26 is open to the exterior through the over= fllow pipe 32,

The function of the cap assembly is essentially the same as that of the assembly 10 previously described The liquid level within the radiator is indicated on the dial means where it may be conveniently read from the exterior in the same manner as illustrated in FIGURE 2. Changes in liquid level are reflected on the dial means by virture of the magnetic coupling between the float assembly and the dial means. Relief of excess positive pressure within the radiator takes place upon movement of the poppet plate 102' upwardly off the lip in opposition to the force of the main spring 106' On the other hand, any appreciable negative pressure in the radiator is relieved by downward movement of the shroud 14' in opposition to the spring 130., Similarly, venting of the radiator to the exterior is accomplished manually by simply pressing downwardly on the dome 82 to move the shroud down away from the poppet plate 102' also in opposition to the spring 130, 7

While certain embodiments of the invention have been illustrated and described in considerable detail, it will be understood that this was only by way of illustration and that. various changes in the constructions and arrange ments of the various parts may be made without departing,

from the spirit and scope of the invention, as defined by the appended. claims.

I claim:

1, A closure cap assembly for a container having an upwardly facing filler neck vertical to the exterior and an. internal shoulder adjacent its juncture with the corn tainer, comprising:

a cap having a central lid portion, a peripheral skirt portion and means on said skirt portion formed to retain association with the filler neck;

an elongated protective shroud supported by said cap for limited vertical movement relative thereto;

means on said. shroud forming an upwardly facing shoulder vertically spaced below the lid portion of said cap;

poppet means disposed around said shroud at vertical. spacing below the lidportion of said cap, said poppet means being arranged for relative vertical movement toward and away from said cap, so as to engage in sealing relationship with the internal shoulder at the juncture of the filler neck and the container and with the shoulder on said shroud;

first spring means urging said poppet means away from said lid portion and into such sealing relationship with said internal shoulder;

second spring means urging said poppet means and said shroud into such sealing relationship;

' a float assembly mounted in said shroud for limited vertical movement relative thereto;

dial means on said cap and including a movable member visible from the exterior of said cap;

and coupling means for controlling the position of said member in accordance with the vertical position of said float assembly 2., The subject matter of claim 1 wherein the spring rate of said first spring means is greater than that of said second spring means.

3. The subject matter of claim 1 wherein said coupling means includes. a magnet and a magnetically attractable member, one of which is connected to the movable member of said dial means and the other of which is disposed in said shroud in operative association with said float assembly,

4.. A closure cap assembly for a container having an upwardly facing filler neck vented to the exterior and an internal shoulder adjacent its juncture with the container, comprising:

a cap having a lid portion with a central aperture, a peripheral skirt portion and means on said skirt por-= tion formed to retain association with the filler neck;

an elongated, hollow shroud formed of a non-magnetic and magnetically 'penetrable material and oriented generally vertically with its upper end projecting upwardly through said aperture in said cap, said shroud being open at its lower end and closed at its upper end and being supported on said cap for limited vertical movement;

means on said shroud forming an upwardly facing shoulder vertically spaced below the lid portion of said cap;

an annular poppet plate disposed around said shroud at vertical spacing below the lid portion of said cap, and arranged for limited vertical movement relative to said cap, said poppet plate being adapted to en-= gage in sealing relationship with said internal shoul der at the juncture of said filler neck and the container and with the shoulder on said shroud;

first spring means urging said poppet plate away from the lid portion of said cap and into such sealing rela-: tionship with said internal shoulder;

second spring means urging said poppet means and said shroud into such sealing relationship;

a float assembly mounted in said shroud for limited vertical and rotational movement relative thereto;

dial means on said cap and including a movable member visible from the exterior of said cap;

and magnetic coupling means including first magnetic means on said dial means and second magnetic means in said shroud and actuated by said float assembly for controlling the position of said member in accord ance with the vertical position of said float assembly.

5, A closure cap assembly for a container having an upwardly facing filler neck vented to the exterior and an internal shoulder adjacent its juncture with the container, comprising:

a cap having a lid portion with a central aperture, a

peripheral skirt portion and means on said skirt portion formed to retain association with the filler neck;

an elongated, hollow shroud formed of a non-magnetic and magnetically penetrable material and oriented generally vertically with its upper end projecting up wardly through said aperture in said cap, said shroud being open at its lower end and closed at its upper end and being supported on said cap for limited verti cal movement relative thereto;

poppet -rneans disposed around said shroud at vertical spacing below the lid portion of said cap, said poppet means being arranged for relative vertical movement toward and away from said cap, so as to engage in sealing relationship with said internal shoulder at the juncture of the filler neck and the container and with said shroud;

means on said shroud accessible from the exterior of said cap when said cap is positioned on said filler neck for shifting said shroud in its limited relative movement to disengage said shroud from said sealing relationship with said poppet means for relieving the pressure within the container;

spring means urging said poppet means away from the lid portion of said cap and into such sealing relationship with said internal shoulder;

a float assembly mounted in said shroud for relatative vertical movement;

a cam assembly mounted in said shroud for relative rotational movement;

means on said float and cam assemblies for producing such rotational movement of said cam assembly in response to such vertical movement thereof;

dial means on said cap and including a movable member visible from the exterior of said cap;

and means for magnetically coupling said cam assembly and said dial means,

6. The closure cap assembly of claim 1 which includes:

translational means for translating said vertical move ment of said float assembly into rotational movement of said coupling means 7; The closure cap assembly of claim 6 wherein said translational means includes:

translational means includes:

means on said float assembly and on said shroud for producing such rotational movement of said float as sembly in response to vertical movement thereof.

9. A closure cap assembly for a container having a filler neck, comprising:

a cap formed to retain association with said filler neck;

an elongated protective shroud supported by said cap for limited vertical movement relative thereto;

valve means within the cap assembly disposed about said shroud at a spaced distance from said cap, said valve means being arranged for relative movement toward and away from said cap so as to engage in and disengage from sealing relationship with said filler neck and said shroud;

means on said shroud accessible from the exterior of said cap when said cap is positioned on said filler neck for shifting said shroud in its limited relative movement to disengage said shroud from such seal= ing relationship with said valve means for relieving the pressure within said container;

spring means urging said valve means into sealing re= lationship;

a float assembly mounted in said shroud for limited vertical movement relative thereto;

indicator means on said cap and including a movable member visible trom the exterior of said cap; and

means for controlling the position of said movable References Cited member in accordance with movement of said float UNITED STATES ATENTS' assembly;

10., The cap assembly of claim 9 wherein said means 762,575 6/1904 Bray, 73-320 for controlling the position of said movable member in 5 794'678 7/1905 Martm cludes magnetic coupling means which includes a magnet 215641676 8/1951 Grouse 73-320 and a magnetically attractable member, one of which is 2,968,421 1/1961 Enshballgh 220-40 connected to the movable member of said indicator means 3'170325 2/1965 Smclalr X and the other of which is disposed in said shroud in op- 3,216,256 11/ 1965 Barnes W 2 X perative association with said float assembly m FOREIGN PATENTS 11. The cap assembly of claim 10 wherein said means for controlling the position of said movable member fur- 18257 8/1904 Great their includes helical means carried in said shroud for LOUIS R PRINCE, Primary Examiner. translating axial movement of said float assembly into ro- DAVID SCHONBERG Emmir'ler tational movement of one of said magnet and said mag- 5 netically attractable n' en'fl gr NIq Assistant Examiner, 

